an easy answer Z.
A better answer, depends on the board, water/spot condition, rider weigh, riding style, sail trim and what purpose you sail (figure 8, downwind, speed). The Sting 2 is an overall good fin, but could slip sometimes upwind, the Z-fin is stiffer and needs a bit more attention downwind but have a better "bite" up wind. But it all comes down to who, where and what. www.andersbq.com/2013/03/obsessed-with-fins.html

markaru27 said..

I am from Aruba so the winds are pretty strong about 20 to 25 knots and choppy waters . i weigh 70 kg and use a 97 lt isonic 2011 with a mauisail tr7 7.0 or 7.6 and i usually sail figure 8 . let me know what you think !

I am not the guy to answer 96 kg is something different. Some guys say that that the isonics are very sensitive to fins. I know some light Aussies that sail isonics. Better you answer!

back on this topic. I have a c3 sting 2 and a z fin zsl both 36 and i like the c3 better. For choppy 18+ knots wind that is. Zfins are better in the sizes 37+ below that i recommend c3 sting 2 or the new Ifins fightclub both almost the same.

I think the general feeling is that fins under 38 there is very little performance difference between G10 and Carbon.
It's not until you get into the bigger sizes that carbon has a slight advantage.
For a IS97 with a 7m for slalom I would be using a 36 sting2 though some sailors can get away using a 34.
The Vipers are also worth looking at they have a tad more control.